Exergoeconomic analysis and optimization of a novel hybrid cogeneration system: High-temperature proton exchange membrane fuel cell/Kalina cycle, driven by solar energy

Highlights: • A proton exchange membrane fuel cell hybrid cogeneration system is proposed. • Kalina cycle and solar methanol steam reformer are integrated with the fuel cell. • Higher cell temperature leads to better economic and environmental performance. • Optimization is done from the viewpoints of thermodynamics, cost, and environment. • An exergy efficiency of 34.84% and a product unit cost of 124.54 $/GJ are achieved. -- Abstract: Designing energy conversion systems with high efficiencies and low pollutant emission is essential for sustainable development. A new cogeneration system including a high-temperature proton exchange membrane fuel cell, integrated with a solar methanol steam reformer, and a Kalina cycle is proposed to produce electricity and heat. Using energy, exergy and cost balance, the proposed system is analyzed from the viewpoints of exergy, economy, and environmental impact. A Parametric study is performed and shows that a higher fuel cell temperature is in favor of the total product unit cost and carbon dioxide mass specific emission. Also, the exergy efficiency is maximized, and the total product unit cost as well as the carbon dioxide mass specific emission are minimized at some specific values of anode recirculation ratio. Optimization results show that the average daily exergy efficiency can increase by up to 29.3% and the total product unit cost as well as the carbon dioxide mass specific emission can decrease by up to 17.72% and 16.3%, respectively compared to the corresponding values under the base conditions. It is concluded that combining a Kalina cycle with a high-temperature proton exchange membrane fuel cell along with utilizing solar energy for reforming process yields an efficient energy conversion system with low emission.